Needle holder

ABSTRACT

A needle holder for use in an image guided intervention procedure. The needle holder includes a clip for holding a needle and a guide arrangement for supporting the clip and directing the needle at a desired angle relative to a patient&#39;s body. The clip includes a releasable connection such that the needle can be disengaged from the guide arrangement by a lateral movement of the clip and/or the guide arrangement relative to the longitudinal axis of the needle.

The invention relates to a needle holder for use in image guidedinterventions. Interventional radiology is a subspecialty of radiologyin which minimally invasive procedures are performed using imageguidance. Some of these procedures are done for purely diagnosticpurposes (e.g., biopsy), while others are done for treatment purposes(e.g., radio frequency ablation). Pictures (images) are used to directthese procedures, which are usually done with needles or small cathetersthat are inserted into the body through the skin or through a bodycavity or anatomical opening. The images allow the interventionalradiologist to guide these instruments through the body to the areas ofinterest.

Common interventional imaging methods include X-ray fluoroscopy,computed tomography (CT), ultrasound (US), and magnetic resonanceimaging (MRI).

When starting an interventional procedure the needle is introduced alittle into the patient from a selected entry point. To verify thecorrect position and direction a set of control images are taken. Due tothe weight of the needle, especially the weight of the portion of theneedle which is outside the body, gravity will deflect the needle fromits intended path. This makes it difficult to ensure that the needlehits the intended target, which can be a small area in the body.

The conventional approach is to advance towards the target by repeatedlyadjusting the angle and inserting the needle little by little whileconstantly taking repeat images to verify position and direction. Everytime an image is acquired any deflection of the needle would make anassessment of the correct direction more difficult. As the depth of theneedle increases more tissue is there to support the needle. However, aheavy needle and/or a long needle would still suffer a deflection due togravity and superficial lesions would not have enough tissue tostabilize a needle.

It is known to use a needle holder to guide and stabilize the needle ata chosen angle during image acquisition. When using a needle holder theuser will get a firm idea of the planned direction of the needle and canuse this information to redirect the needle until the correct angle isobtained. Once the desired angle is obtained the needle holder can helpto steer the needle in the chosen direction, and when the needle is atthe correct position the needle holder can be used to fix the needle ata chosen depth (when using a coaxial approach). Longer needles and/orheavier needles would typically need more support than short and lightweighted ones.

Examples of known needle holders can be found in U.S. Pat. No.4,883,053, U.S. Pat. No. 5,201,742 and WO 2004/021898. These documentsdisclose the use of a plate or base which is placed onto the patient andsupports two guide members that intersect at an angle. The guide membersare typically semi-circular or segments of a circle which are connectedat their ends over two diameters of a circular base, where the diametersintersect at right angles. One or both of the guide members is connectedto the base with hinges that enable rotation of the guide member todifferent angles. A clip or a tube for holding the needle is joined tothe guide members in such a way that the needle can be pointed at anyangle relative to the plane of the base. This is achieved by allowingthe clip or tube to slide relative to one or both of the guide members,and by changing the angle of the guide members. A screw fitting can beused to tighten the connection between the clip or tube and the guidemembers, and/or between two guide members in order to fix the needle inplace.

It is also known in alternative embodiments in some of the abovereferences to use a spherical or part-spherical member which is moveablymounted to a part-spherical bearing surface to enable a needle passingthrough the spherical or part-spherical member to be pointed at adesired angle.

However, whilst these prior art devices can provide the necessarystability and guidance for a needle in an interventional radiologyprocedure, they restrict the actions of the radiologist in subsequent orpreceding handling of the needle.

Viewed from a first aspect, the present invention provides a needleholder for use in an image guided intervention procedure comprising: aclip for holding a needle and a guide arrangement for supporting theclip and directing the needle at a desired angle relative to thepatient's body; wherein the clip includes a releasable connection suchthat the needle can be disengaged from the guide arrangement by alateral movement of the clip and/or the guide arrangement relative tothe longitudinal axis of the needle.

In the prior art, the needle is secured to the guide members in such away that the needle can only move relative to the guide member along thelongitudinal axis of the needle. Thus, in order to remove the needlefrom the guide arrangement the whole length of the needle must passthrough the needle holder. The inventors have realised that this createssignificant problems for the user, as it means that the user cannotabort the use of the needle holder without retracting the needle fromthe patient. The prior art needle holders must remain in place whilstthe needle is in use during an interventional. procedure. The clip ofthe present invention allows the needle to be released from the guidearrangement by a lateral movement, and thus enables the needle holder tobe disconnected from the needle at any stage, and at any point along thelength of the needle. The needle holder of the invention canadvantageously be removed from the needle and from the patient withoutmoving the needle relative to the patient's body. The user can decidepart-way through a procedure if a needle holder is or is not necessary,and can connect or disconnect the needle holder accordingly. The needlemay remain in place during disengagement of the clip, because thelateral movement permits removal of the clip without the need formovement of the needle relative to the body. In addition, once theneedle has been inserted sufficiently for the body tissue to provideappropriate support and guidance, the needle holder of the presentinvention can be disconnected to enable full insertion of the wholelength of the needle if required. The needle holder preferably comprisesa base for supporting the needle holder on the patient's body.Advantageously, the lateral movement of the clip and/or the guidearrangement is a movement of the clip and/or the guide arrangementwithout requiring movement of the needle relative to a base of theneedle holder. Although in some instances it may be beneficial to movethe base away from the patient's body as the needle is disconnected, itwill often be desirable to disconnect the needle without movement of theneedle relative to the body. By using an arrangement that does notrequire movement of the base relative to the needle, both the base andthe needle can remain in situ as the clip is released. Once disconnectedfrom the needle, the needle holder can be easily removed.

Advantageously, the clip holds the needle by releasably securing theneedle to the needle holder.

The releasable connection may comprise a connection between the clip andthe guide arrangement and/or a connection between the clip and theneedle. In a preferred embodiment, the releasable connection enables theneedle to be disconnected from the clip by a lateral movement of theclip relative to the longitudinal axis of the needle. This arrangementmeans that the needle can be released from the guide member and alsofrom the clip.

Preferably, the clip includes a first connector for releasableengagement with the guide arrangement, and a second connector forreleasable engagement with the needle. With this arrangement, the clipcan be fully disconnected from both the guide arrangement and theneedle, and this makes removal of the needle from the needle holdereasier. In a preferred embodiment one connector is engaged by a lateralmovement of the clip relative to the longitudinal axis of the needle andthe other connector is engaged by a longitudinal movement relative tothe longitudinal axis of the needle. The first connector may use alateral movement, and the second connector may use a longitudinalmovement. In this case, the needle is released from the guidearrangement by removing the clip from the guide arrangement. However,this leaves the clip connected to the needle. Therefore, in a preferredembodiment of the invention the first connector uses a longitudinalmovement, and the second connector uses a lateral movement.Advantageously, this means that the clip may be removed from the guidearrangement by a movement of the clip along the length of the needle,and the clip can then be removed from the needle by a lateral movement.This means that neither the guide arrangement nor the needle aredisturbed from their positions. Instead, the clip can be completelydisengaged by movement of the clip alone.

The releasable connection may comprise any suitable mechanism. Forexample, a two part clip may be provided that can be fitted around aguide member of the guide arrangement and the needle by means of a screwthread, bayonet type fitting or the like. Preferably however, thereleasable connection is achieved using a friction fit and/or resilientportions on the needle holder, such that the clip can be formed withoutmoving parts, preferably as a single part, and can be connected to theneedle and/or guide arrangement by pushing the clip toward the needleand/or guide arrangement respectively.

In a preferred embodiment the clip comprises a first connector andsecond connector as discussed above, wherein the first connector joinsto a guide member of the guide arrangement by a tongue and groovearrangement. Advantageously, such a tongue and groove arrangement mayallow the clip to slide along the guide member in order to place theneedle at a desired angle and/or position. The tongue and groovearrangement may comprise a first channel on the clip for engagement witha tongue in the form of a rail portion of the guide member. The secondconnector may comprise a second channel for receiving the needle.Preferably, the first channel intersects the second channel, such thatwhen the rail portion is inserted in the first channel, it preventsremoval of the needle from the second channel. This arrangement allowsthe connection of the clip to the guide member to lock the needle inplace, and hence avoids the need for an additional locking/closing pieceto secure the needle. The first channel may, for example, extend normalto the second channel and pass across the second channel part way alongthe second channel so that the cross-sections of the two channels form across or T-shape when viewed along the longitudinal axis of the needle.With this arrangement, when the clip is in place, the rail portionbridges the second channel to block movement of the needle out of thesecond channel.

In order to ensure that the clip fits securely to the guide member, thefirst connector preferably includes a securing arrangement for providinga tightening connection as the clip is pushed onto the rail portion.This may be a resilient portion and/or an section of varying width onthe clip and/or the rail potion. Preferably, the clip is arranged suchthat as the connection of the first channel with the rail portion istightened, the needle is also more tightly engaged with the secondchannel. This may be achieved by clamping the needle between the railportion and the base of the second channel. The base of the secondchannel may be the same surface as a side of the first channel. Theneedle holder may include a ridge and slot arrangement to guide the clipalong the guide member. For example there may be a ridge or slot on aninternal surface of the first channel, and a complimentary slot or ridgeon an external surface of the rail portion. Engagement of a ridge with aslot can be used for guidance of a sliding motion of the clip along theguide member. In addition, this engagement can be used to positivelysecure the clip in a desired position.

The clip preferably includes a releasing device for facilitatingdisengagement of the clip from the rail portion. The releasing devicemay comprise lever portions for opening a channel or groove of thesecond connector. The opening may be achieved by resilient deformationof the clip.

The clip may be connectable to the needle and guide arrangement in twoorientations, for example by rotating the clip through 180°. This mayenable the clip to engage with the needle and/or guide arrangement intwo different ways. In a preferred arrangement of this type, the clip,includes a third connector in addition to the first connector, whichjoins to the guide member of the guide arrangement by a tongue andgroove arrangement in a way similar to the first connector, and whichpreferably comprises a third channel, wherein when the rail portion isinserted in the third channel, it prevents removal of the needle fromthe second channel. The first connector may comprise a ridge or slot forengagement with a corresponding ridge or slot on the rail portion, inorder to provide a guided sliding motion of the clip along the railportion and/or to lock the clip in place. A second ridge or slot on therail portion or the clip may provide a tighter coupling between the clipand guide member. In a particularly preferred embodiment, a ridge of thefirst connector engages with a first slot when pushed a first distanceover the rail portion, which provides a guided sliding connection, andengages with a second slot when pushed further onto the rail portion,which fixes the clip in place. Preferably, the channel of the firstconnector intersects with the channel of the second connector such thata recess is provided for the needle, and the needle can be moved evenwhen the first connector is fixed in place on the rail portion. Withthis arrangement, the third connector is preferably arranged to providea tightening connection which securely fixes the clip and needlerelative to the guide member. For example, a wedge shaped element may beused, for providing a resilient and/or friction fit between the clip andguide member.

The first connector and third connector may be on opposite sides of theclip such that either the first connector or the third connector can beselected to join the clip and optionally the needle to the guide member.In this way, the user can select if they want the needle to be securelyheld or not, by turning the clip to use the first connector or the thirdconnector to join to the guide member.

The preferred clip and guide arrangements enable the connection betweenthe needle and guide arrangement to be achieved using only one movingpart. This is important for use in a medical environment and forcleaning, as it reduces the risk of contaminants, bacteria and so onbeing found in the clip. Moreover, the design of the clip enablesmedically compatible materials to be used, such as appropriate medicallycompatible plastics, which can readily be sterilised.

Preferably, the connectors of the clip have a degree of tolerance, suchthat the clip can securely support a needle even if the needle is not atthe centre of the needle holder and/or the clip can securely support aneedle at a range of angles relative to the clip. For example, thesecond channel may be larger than the desired needle size so that theneedle sits loosely in this channel until secured in place. Thisarrangement makes it easier to connect and reconnect the needle holderpart-way through a procedure, and also provides additional flexibilityin adjustment of the needle position and angle.

In a preferred embodiment, the needle holder includes a base forsupporting the needle holder when placed on a body surface. The base mayinclude an adhesive layer for joining the needle holder to the body. Thebase should include a hole to allow passage of the needle from the guidearrangement to the body surface. Preferably, the hole has an opening inits perimeter, i.e. the base does not fully enclose the hole. Thisenables the user to fully remove needle holder from patient after theneedle is disengaged from the guide arrangement, without the need tolift the needle holder base over the needle. Full engagement anddisengagement of the needle holder can hence be achieved at any stage.

The base may include an arrow shaped portion, with the arrow preferablybeing directed toward the centre of the hole. The arrow shaped portionaids in centring the needle holder on the desired location on the bodysurface. Preferably, a plurality of arrow shaped portions are present,and these may be located symmetrically about the centre of the hole.

The guide arrangement may be any suitable mechanism for allowing theneedle to be directed into the body at a range of angles. For example,guide arrangements similar to those in the above referenced prior artdocuments may be used, provided they can be adapted to work with thereleasable clip of the present invention. In a preferred embodiment, theguide arrangement comprises a first guide member, and a second guidemember. The first guide member corresponds to the guide member referredto above, and comprises a rail portion forming a segment of a circle.This first guide member may be supported by hinges on a base. The hingesallow the first guide member to be placed at any angle to the base,across an arc of about 180°. The second guide member is for enablingcontrol of the angle of the first guide member. The second guide memberpreferably takes the form of a segment of a circle located adjacent oneend of the first guide member, wherein the guide arrangement includes areleasable clamp for joining the two guide members, and the releasableclamp is arranged to releasable secure the first guide member to thesecond guide member at any angle. The releasable clamp may comprises ascrew fitting.

The needle holder can be used with any conventional interventionalimaging method, for example with CT guidance or fluoroscopic guidance.For CT guided procedures the skin surface is marked and so the needleholder can be centred about the skin entry point by aligning the basewith the markings. However, for other techniques, such as fluoroscopicguidance, this is not the case. With fluoroscopic guidance x-rays areused to visualize the needle axis and direct it towards a lesion. Toensure that the needle holder can be accurately aligned with the targetarea during the use of x-ray imaging or other imaging techniques wherethe skin is not marked the needle holder may include markers. Themarkers should be visible with the desired imaging method. For example,radio opaque markers may be used for x-ray imaging. The use of markersensures that the needle holder can be visualised. The markers arepreferably located on the arrow shaped portions of the base to allowalignment of the base with the target area and/or located on the clip toallow visualisation of the clip position and orientation.

As is known, some image guided procedures involve the use of multipleneedles, each of which needs to be inserted into the body in acontrolled way to target a particular site. An example of such aprocedure is radio frequency (RF) ablation. A preferred embodiment ofthe needle holder includes a plurality of releasable clips, each forholding a needle on the guide arrangement. In this way, multiple needlescan be located on a single guide arrangement and directed at differentangles. Preferably, the guide arrangement includes a first guide memberas discussed above and the circular arc of the segment of a circle thatforms the rail of the first guide member is centred on a point beneaththe base. With this arrangement, when two needles placed at differentangles using two clips on the first guide member, the longitudinal axesof the two needles on the guide member will converge on a point belowthe skin.

Preferably, the needle holder is provided with multiple guidearrangements which are arranged for directing one or more needles atdifferent angles. For example, there may be two first and second guidemembers of the type discussed above, with each first guide member beingrotatable relative to the base. The arcs of rotation of the two firstguide members may be centred along parallel lines spaced apart suchthat, when, in use, needles are guided from each of the two first guidemembers at an angle into the patient's body, the longitudinal axes ofthe two needles on the different guide members will converge on a pointbelow the skin.

In a preferred embodiment, there are two first guide members, as above,centred on parallel lines that are spaced apart, and each of thecircular arcs of the segment of a circle that form the rails of the twofirst guide member are centred on points at the same depth beneath thebase. With this arrangement two or more needles held by clips on each ofthe two first guide members (e.g. at least four needles in total) can bedirected into the patient's body in a symmetrical fashion.

Each clip of the multiple clips is releasable and the use of a lateralmovement relative to the needle to disengage the clip enables all theclips and hence the needle holder to be disengaged from the plurality ofneedles without movement of the needles. Hence, multiple needles can belocated, as desired, and then the needle holder can be removed to permitunimpeded access to the patient during the procedure.

It will be appreciated that different interventional procedures requiredifferent sizes of needle. The clip of the present invention may be madewith sufficient tolerance to accommodate a range of needle sizes. In apreferred embodiment, a number of clips for fitment to different sizesof needle are provided in order to allow an increased range of needlesize. Advantageously, the different sizes of clip may be used with thesame guide arrangement, as the clips can be disengaged and replaced.Hence, the invention extends to a needle holder kit comprising a needleholder as set out above, with a clip for needles of first size, and atleast one additional releasable clip, the additional clip being forneedles of a second, different, size. There may also be one or morefurther additional clips, for needles of a third, different, size, afourth, different, size and so on. Multiple clips of each size may beprovided. This will enable use of the needle holder with multipleneedles of each different size.

A preferred embodiment of the invention will now be described by way ofexample only and with reference to the accompanying drawings in which:

FIG. 1 is an exploded view of a needle holder, with a first embodimentof a clip;

FIG. 2 is a perspective view of the needle holder of FIG. 1 with theneedle present and being supported with its longitudinal axis normal tothe base;

FIG. 3 shows the needle holder of FIG. 2 from the reverse side, with theclip removed from the first guide member and needle;

FIG. 4 illustrates rotation of the first guide member, in this case withthe needle disengaged;

FIG. 5 shows the needle holder being withdrawn from the site of theprocedure, with the needle remaining in place;

FIG. 6 illustrates a similar needle holder, with a second embodiment ofa clip

FIG. 7 shows the needle holder of FIG. 6, with the clip in a secondorientation;

FIG. 8 shows the clip of FIG. 6 in greater detail;

FIG. 9 is a cross-section with the clip of FIG. 6 in a first position;

FIG. 10 is a similar cross-section showing the clip of FIG. 6 in asecond position; and

FIG. 11 shows a cross-section the clip in the second orientation, as inFIG. 7.

As shown in FIG. 1, the needle holder is made up of a base 1, firstguide member 2 and clip 3. The components of the base 1 each have a hole4 at the centre, the hole 4 having an opening in its perimeter.

The base 1 comprises a rigid base plate 11, a flexible layer 12 and atape layer 13, which is an adhesive tape. The flexible layer 12 and tapelayer 13 have four arms extending outwardly from the central hole 4.These arms enable the base 1 to be adhered to the patient in a secureand flexible manner, if required, by means of the adhesive tape. Thebase plate 11 includes four arrow shaped portions 14, with the arrowsbeing directed toward the centre of the hole 4. These arrow shapedportions 14 aid in centring the needle holder on the desired location onthe body surface. Markers such as radio opaque markers can be placed onthe arrow shaped portions 14 and also on the clip 3 to permitvisualisation and alignment of the needle holder with a target areaduring an imaging procedure.

The first guide member 2 is an inverted U-shape, with two legs 21supporting a rail portion 22, which is a segment of a circle. At thebase of each of the legs 21 is a hinge member 23, for engagement with abracket on the base plate 11. The hinge member 23 allows the first guidemember 2 to pivot relative to the base 1. The base plate 11 incorporatesa second guide member 5, which in this embodiment is formed integrallywith the base plate 11. The second guide member 5 is a half circle,which is located adjacent one leg 21 of the first guide member 2 whenthe first guide member 2 is fixed to the base 1.

To enable controlled adjustment of the angle of the first guide member2, the first guide member 2 includes a clamp mechanism 24. The clampmechanism 24 comprises a screw thread integrally formed with the firstguide member 2, and a washer and nut for attaching to the screw thread.The clamp mechanism 24 is tightened by screwing the nut onto the thread,and pressing the washer up against the second guide mechanism 5, toclamp it between the washer and the leg 21 of the first guide member 2.This can be seen more clearly in FIGS. 2 to 5.

In FIG. 2 the needle holder of FIG. 1 is assembled and is in usesupporting a needle 6, which is clamped between an internal surface ofthe clip 3 and the rail portion 22 of the first guide member 2. Thehinges 23 are secured in the brackets on the base 1, and allow rotationof the first guide mechanism 2 relative to the base 1. The clampmechanism 24 is engaged with the second guide mechanism 5 in order tosecure the first guide mechanism 2 at an angle of about 90° to the base1. The clip 3 is engaged with the first guide mechanism 2 such that theneedle 6 is held vertically, i.e. normal to the body surface that thebase 1 is supported by. The needle 6 can be inserted into the bodythrough the hole 4.

It will be appreciated that the needle 6 can be supported at any desiredangle by adjustment of the position of the clip 3 on the rail portion22, and by adjustment of the angle of the first guide mechanism 2 to thebase 1 using the second guide mechanism 5. The needle holder can thus beused to guide a needle into the body as discussed above.

The clip 3 includes a first channel 31, which fits over the rail portion22, and a second channel 32, which allows the needle 6 to be inserted inthe clip 3. These parts of the clip 3 can be seen more clearly in FIG.3, which shows the clip 3 disengaged from the first guide mechanism 2and the needle 6. As shown in FIG. 3, the first channel 31 is formedbetween two outer flange portions of the clip 3, which extend in agenerally vertical plane in the Figures. A central portion 33 joins thetwo outer flange portions, and extends in a generally horizontal planein the Figures. Thus, in side view, i.e. viewed along the plane of thefirst guide mechanism 2 in FIG. 3, the clip 3 has a H-shape. The firstchannel 31 is formed by the lower half of the H-shape, between the twolegs of the H. The second channel 32 is at right angles to the firstchannel 31, and cuts through one of the outer flange portions andthrough the central portion 33. The first channel 31 thus cuts throughthe second channel 32.

To secure the needle 6 to the needle holder, the clip 3 is movedsideways onto the needle 6 so that the needle 6 is placed in the secondchannel 32. Then, the clip 3 is slid along the length of the needle 6 sothat the first channel 31 is pushed over the rail portion 22. Thesemovements are shown by the dashed line 7 in FIG. 3. The rail portion 22hence blocks movement of the needle 6 out of the second channel 32.

When the clip 3 is engaged with the rail portion 22, the needle 6 isclamped between the rail portion 22 and the internal surface of one ofthe outer flange portions of the clip 3. The clip 3 is arranged to fittightly onto the rail portion 22 so that the needle 6 is securely heldin place, and to this end the rail portion 22 includes ridges whichengage with grooves on an internal surface of the clip 3. When the clip3 is fully pushed onto the rail portion 22 there is a snap fit whichlocks the clip 3 in place. If the clip 3 is not fully pushed onto therail portion 22 then it can slid along the ridges to enable adjustmentof the needle angle. For a large adjustment of angle, the clip 3 can befully removed, if required.

The clip 3 is composed of a resilient material, so it can be releasedfrom the rail portion 22 by pressing the two upper portions of the outerflanges together, which form lever portions for moving the two lowerportions apart and widening the first channel 31. Thus, the clip 3 canbe resiliently deformed by flexing the central portion 33.

In FIG. 3, the clip 3 has been completely removed, and the first guidemember 2 has been bent down away from the needle 6 as shown by thearrow. To do this, the clamp mechanism 24 can be loosened from thesecond guide member 5. This enables the needle 6 to be moved and/orfully inserted without hindrance. If required, the needle holder can befully removed from the insertion area, by sliding the needle holder awayfrom the needle 6 and passing the needle 6 through the opening of thehole 4, as shown in FIG. 5.

FIGS. 6 and 7 show a needle holder with a second embodiment of a clip 3.Other features of the needle holder in the second embodiment are thesame as for FIGS. 1 to 5, as discussed above. The clip 3 is shown in afirst orientation in FIG. 6, and in a second orientation in FIG. 7,where it is turned upside down compared to FIG. 6.

The clip 3 of the second embodiment includes a first channel 31, asecond channel 32, two outer flange portions and a central portion 33 asin the first embodiment. The clip 3 of the second embodiment also makesuse of a third channel 34. In the first orientation, the first channel31 is engaged with the rail portion 22, and in the second orientationthe third channel 34 is engaged with the rail portion 22. Engagement ofthe first or third channel is carried out by moving clip 3 sideways ontothe needle 6 so that the needle 6 is placed in the second channel 32 andthen sliding the clip 3 is slid along the length of the needle 6, asdiscussed above in relation to the first channel of the firstembodiment.

The first channel 31 and third channel 34 of the clip 3 of the secondembodiment can be seen in more detail in FIG. 8. The first channel 31includes two ridges 35, and the third channel 34 includes two wedgeshaped portions 36. These wedges 36 increase in width toward the middleof the clip 3. The second channel 32 intersects both the first and thethird channels. The first channel 31 is narrower than the third channel34, such that the second channel 32 extends beyond a side edge 37 of thefirst channel 31 to form a recess for the needle 6. The third channel 34is wider, and a side edge 38 of the third channel 34 forms a continuoussurface with the base of the second channel 32.

Operation of this clip 3 can be seen in FIGS. 9 to 11, which show detailof the clip 3 in cross-section for two positions in the firstorientation, and also in the second orientation.

In FIG. 9 the clip is in the first orientation (as in FIG. 6), and hencethe first channel 31 is engaged with the rail portion 22 of the guidemember 2. The rail portion 22 includes two slots 25, 26 which are sizedto fit the ridges 35 on the first channel 31 and are at a first andsecond height on the rail portion 22. In the first position of FIG. 9,the ridges 35 are engaged with the upper slot 25, and the first guidemember 2 is hence held loosely within the first channel 31, such thatthe clip 3 can be slid to adjust the angle of the needle 6. If the clip3 is pushed further onto the first guide member 2, the ridges jump in asnap fit from the upper slot 25 to the lower slot 26, as shown in FIG.10. At the same time, an outwardly angled surface 27 of the first guidemember 2, which is opposite the slots 25, 26, engages with the side edge37 of the first channel opposite the ridges 35, and the clip 3 is lockedin place by resilient deformation of the clip 3 and first guide member2. With the clip 3 in the first orientation, the needle 6 cannot beremoved from the second channel 32, but is free to move with the secondchannel 32 due to the recess formed beyond the side edge 37 of thechannel. The needle 6 is shown placed against the angled surface 27 ofthe first guide member 2, and is free to move away from this surface 27as far as the side edge 38 of the third channel 34, i.e. a movement tothe right in the views shown in FIGS. 9 and 10.

FIG. 11 shows the clip 3 in its second orientation, upside down comparedto FIGS. 9 and 11. The cross-section of FIG. 11 is translated into thepage compared to the cross-sections of FIGS. 9 and 10, and cuts throughthe centre of the needle 6 and through the centre of the second channel32. A wall 39 of the second channel can hence be seen. This Figure alsoillustrates how the second channel 32 cuts through the central portion33 of the clip 3. In this orientation of the clip 3 the needle 6 can besecurely fixed at a desired angle, by pushing the first guide member 2between the wedges 36 and the needle 6. The rail portion 22 is pressedup against the wedges 36, and the outwardly sloped surface 27 is pressedup against the needle 6. This traps the needle 6 between the first guidemember 2 and the side edge 38 of the third channel 34. Pushing the firstguide member 2 further into the third channel 34 tightens theconnection.

As for the first embodiment, the clip 3 is composed of a resilientmaterial, so it can be released from the rail portion 22 by pressing thetwo upper portions of the outer flanges together, which form leverportions for moving the two lower portions apart and widening either thefirst channel 31 or the third channel 34, depending on the orientationof the clip 3. The needle holder would typically be supplied sterilisedand packed in a sterilised pouch for single use, and use of the needleholder might proceed as follows:

1. Clean, disinfect and cover the chosen entry point in a conventionalmanner.

2. Unpack the needle holder.

3. Centre the needle holder over the entry point using the four arrows14 in the base plate 11 or markers located on the arrows 14. If a needle6 is already in place locate the needle holder around it and centre thebase 1 over the entry point.

4. Raise the first guide member 2 until it supports the needle 6 andfasten the screw of the clamping mechanism 24.

5. Chose the correct releasable clip 3 (for example, three or more sizesmay be supplied for different needle thicknesses).

6. Attach the releasable clip 3 by movement along the dashed line 7 inFIG. 3, as discussed above.

7. If needed loosen the clamping mechanism 24 and/or the releasable clip3 and adjust the positions of the first guide member 2 and clip 3 untilthe chosen needle angle is obtained. If the clip 3 of the secondembodiment is used then this process will have the clip 3 in the firstorientation.

8. Tighten the clamping mechanism 24 and push down the clip 3 to engagethe snap fit, and thus secure the needle 6 at the chosen angulation. Ifthe clip 3 of the second embodiment is used then this process will havethe clip 3 in the second orientation.

9. Take a control image to verify the angulation. If not correct repeatsteps 7-9.

10. If the control image confirms that the proper puncture route isobtained then loosen the clip 3 and insert the needle 6 further usingthe needle holder as stabilizer and guide.

11. Should there be a need to readjust the angulation loosen theclamping mechanism 24 and the clip 3 and align the needle 6 again.

12. Should there be a need for a large correction the clip 3 can beremoved completely and the first guide member 2 pushed away.

13. If working with a coaxial system the needle holder can be used tosecure an introducer needle in front of a lesion by changing the clip 3to an undersized version. This means that the introducer needle is morefirmly secured and will not be inadvertently pushed further in bymanipulation of the inner needle. The clip 3 of the second embodiment isparticularly suited to securing an undersized needle when in the secondorientation. Alternatively a locking mechanism can be provided on theclip 3

14. The first guide member 2 can be reattached or removed depending onthe need for support, and if required the needle holder can becompletely removed as in FIG. 5.

If the interventional procedure requires multiple needles, then one ormore additional clips and additional needles can be added by repeatingsteps as required.

The needle holder is made of different plastic materials, which areselected for their physical properties and to be compatible with variousforms of sterilization among others ETO. Thus, the base plate 11 andguide members 2, 5 are polycarbonate, which is rigid and provides therequired support. The clip 3 and the nut of the clamping mechanism 24are polyurethane, which provides the required resilience. Bothpolycarbonate and polyurethane can be easily moulded into the desiredshapes. The flexible layer 12 is made of a polyester.

1. A needle holder for use in an image guided intervention procedurecomprising: a clip for holding a needle and a guide arrangement forsupporting the clip and directing the needle at a desired angle relativeto a patient's body; wherein the clip includes a releasable connectionsuch that the needle can be disengaged from the guide arrangement by alateral movement of the clip and/or the guide arrangement relative tothe longitudinal axis of the needle.
 2. A needle holder as claimed inclaim 1, wherein the releasable connection comprises a connectionbetween the clip and the guide arrangement and/or a connection betweenthe clip and the needle.
 3. A needle holder as claimed in claim 1,wherein the releasable connection enables the needle to be disconnectedfrom the clip by a lateral movement of the clip relative to thelongitudinal axis of the needle.
 4. A needle holder as claimed in claim1, wherein the clip includes a first connector for releasable engagementwith the guide arrangement, and a second connector for releasableengagement with the needle.
 5. A needle holder as claimed in claim 4,wherein one connector is engaged by a lateral movement of the cliprelative to the longitudinal axis of the needle and the other connectoris engaged by a longitudinal movement relative to the longitudinal axisof the needle.
 6. A needle holder as claimed in claim 5, wherein thefirst connector uses a longitudinal movement, and the second connectoruses a lateral movement.
 7. A needle holder as claimed in claim 4,wherein the first connector joins to a guide member of the guidearrangement by a tongue and groove arrangement that allows the clip toslide along the guide member in order to place the needle at a desiredangle and/or position.
 8. A needle holder as claimed in claim 7, whereinthe tongue and groove arrangement comprises a first channel on the clipfor engagement with a tongue in the form of a rail portion of the guidemember.
 9. A needle holder as claimed in claim 8, wherein the secondconnector comprises a second channel for receiving the needle, and thefirst channel intersects the second channel, such that when the railportion is inserted in the first channel, it prevents removal of theneedle from the second channel.
 10. A needle holder as claimed in claim4, wherein the first connector includes a securing arrangement forproviding a tightening connection as the clip is pushed onto the railportion.
 11. A needle holder as claimed in claim 10, wherein the clip isarranged such that as the connection of the first channel with the railportion is tightened, the needle is also more tightly engaged with thesecond channel.
 12. A needle holder as claimed in claim 4, wherein theclip is connectable to the needle and guide arrangement in twoorientations.
 13. A needle holder as claimed in claim 12, wherein theclip includes a third connector, which joins to a guide member of theguide arrangement by a tongue and groove arrangement.
 14. A needleholder as claimed in claim 13, wherein the third connector comprises athird channel on the clip for engagement with a tongue in the form of arail portion of the guide member, and wherein when the rail portion isinserted in the third channel, it prevents removal of the needle fromthe second connector.
 15. A needle holder as claimed in claim 14,wherein the third connector is arranged to provide a tighteningconnection which securely fixes the clip and needle relative to theguide member.
 16. A needle holder as claimed in claim 4, wherein thefirst connector comprises a ridge or slot for engagement with acorresponding ridge or slot on a rail portion of the guide arrangementin order to provide a guided sliding motion of the clip along the railportion and/or to lock the clip in place.
 17. A needle holder as claimedin claim 16, wherein a second ridge or slot on the rail portion or theclip is arranged to provide a tighter coupling between the clip andguide member.
 18. A needle holder as claimed in claim 4, wherein, achannel of the first connector intersects with a channel of the secondconnector such that a recess is provided for the needle, and the needlecan be moved even when the first connector is fixed in place on theguide arrangement. 19-22. (canceled)
 23. A needle holder as claimed inclaim 1, comprising a base for supporting the needle holder when placedon a body surface, wherein the base includes a hole to allow passage ofthe needle from the guide arrangement to the body surface.
 24. A needleholder as claimed in claim 23, wherein the hole has an opening in itsperimeter. 25-26. (canceled)